Joint for metal casings.



A. SMITH.

JOINT FOR METAL CASINGS.

APPLICATION man umn-25. |915..

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A. SMHH. ,Y0-INT FOR METAL CASINGS. ARPLlcATNm man MAR.25.1915.

Patented Mar. 4,1919.

2 SHEETS-SHEDi 2 Tof/3m of each section, the

pressure without stripping the threads.`

ANDREW sMITH, or sen MATEO, camronmn. JOINT For. METAL cAsINes. l

well-strainers or curbings, etc., and more particularly to the construction of the joints by which the sections of the` casing are connected, this case beine a division of my prior Patent N o. 1,165,135?, dated December 21, 1915.

The common coupling most generally employed for uniting tubing consists of a socket `d screw-threaded on the interior, and a corresponding screw-thread formed on the ends tions being then screwed into the coupling.

When the tubing is used `for casings for wells which frequently extend to a depth of several' hundred feet it is necessary that the j ointshould be capable of resisting enormous strains and'ofsustaininggreat weight and Againwhen the tubing is used for pipe-lines and similar purposes, where it is often subjected to severe lateral or bending strains, it has been found that the threaded joint is the weakest part of the conduit and the cause of most of the failures.

thickness of the metal walls has been increased in order to permit the cutting of deeper threads without a too great wea ening of the metal at the joint. This increased thickness of the tubing adds materially to the weight and costand the increased weight of the tu ing increases the cost of shipment and adds also to the expense of handling the pipe at'the place of installation.

l more it greatly increases the `weight of metal j a coupling that `must be sustained when the tubingis used for well oasings. v One ob ject of my invention is stronger, to resist strains due to longitudinal tension or compression, and alsolateral or bending strains. A her object is to reinforce the metal at the joint and also adjacent the joint so that the casing may be manipulated 'by tongs or other implements Specification of Letters Patent.

Original application filed .Tuly 29, 1913, Serial No. 781,820. Divided and 1915. Serial No. 17,010.

States, residing at San adjacent ends of the secmeeting ends of modied form of For this reason the inner side, as shown in Fig. 1, or y"preferable in Furtheror threads in each "at the same time, Haring to provide which will -be as strong at'the f `joint as the main body of the casing, or even Patented Mar. 4i, 1919.. this application led March 25,

without injury. `A further object is to provide a casing in which there is no contraction of the internal capacity or area through the joint `or coupling portion. Other purposes of my invention will be apparent from the following detailed description.

In the accompanying drawings, Figuresl and 2 are longitudinal sections showing portions of casing units provided with reinforced joints embodying my invention; Fig. 3 is a longitudinal section showing a modiication of the oint shown in Fig. 2, with the longitudinal view, partly in section, showing my reinforced joint or coupling applied to a uplex perforated casing or strainer, which single-walled strainer casing; and Fig. 7 ,is

of the pipe sections showing a my joint.

In order `o provide a reinforcement of the metal at the joint, I ffold back or return the a longitudinal View, partly in section `metal' upon itself while in the sheet a distance suiiicient to cover the joint and the adjacent portion which receives the gripping tongs when the pipe or casing is being manipulated. The sheet is then'shaped into tubular form and the meeting edges are welded to form a longitudinal seam, preferably by theoxyacetylene or by the electric arc welding processes. The pipe or casing may be formed with Vthe reinforcement upon the upon the outer side as shown in Fig. 2, the latter being most cases.

After the casing units have been formed as above described, I roll spiral corrugations end the required distance,

one end into a bellshape or mouth as at la, to form the outer member and correspondingly tapering the otherend as at 1b, to form the inner member.Y Byf rolling the spiral corrugations or ds into the metal after. it has been folded back upon itself, both layers of metal partake of the thread formation and every reinforced. In order that the internal diameter of the tapered end shall not be less than `outer.member slightlynnd in.` the other case, 60.

' ber.- intoasligbt taper,

Y itself ,whilein :the sheet, I ma metal instead of aquadruplethickness,

sinner member isvone of' tion upon. one end.

no contraction 1n the bore of the pipe or obstruction offered by the parts forming the oint.

The plain extended portions 3 reinforce those portions of the casing Which areI grasped by the tongs or clamps when the pipe is being inanipulated, -as for instance, Whenthe` sections or units are being screwved together.- and when' a Well casing is being flowered'into a Well. This extended reinforcementalso adds rigidity to the end p0rtions which serves as :a protection during the rough liandlingiof shipment. The conformation .of `the spiral .corrugations `or threads is insured by the double thickness of metal, every part of 4.which is reinforced.'

Instead ofgfolding the Ymetal back upon 11 slip an outer sleeve-over a single tubulancasing and Weld the .two :together to formY an integral reinforced-structure and then rollthe Vthreads therein as ishown i-n Figs. Sand 4. In this manner I may. use reinforcing members of rdi-Eerent thicknesses to suit varying conditions t0 which the casing Amay., be subjected.

In some yeases I iind itlsuiiicient to reinforce only one end ofthe sections, thereby forming a joint having a triple thickness of as. inthe forms `previously described.` In vthis formcasillustrated in Fig. 6, I prefer to reinforce the outer-,oniiared l`end asthis must resist the outward pressuretending to stretch or` rupture the metal as the pipe ends are screwed together.; While the action upon the Y compression and it is Vwell known-.that metal will offer greater resistance. to compressions than `to stretching or. expansion. Under` many conditions this reinforcement ofthe outer in ember only,

.giving a threefold Wall in the j enit-is ample in c strength ,toy support and resist all the strains to which it may be subjected and with a large reserve or factorof safety.

While I prefer to taper one end and correspondingly flare4 the other end of the units or sections as previouslydescribed, I may insome cases dispense with the conical fo-rma- That is, I'may either taper one .end ,and -form the other end ofa amiformxliameter, or I may flare the endforming the outer memberi of the joint and inakethe .othenend of uniform diameter. In the first case, the tapered end `stretches the f the outer -member compresses the innenmem- .so that both -cases theinner and outer members .con-form to each other. as the parts aresrewed together.

In Jg. 7 I -vhave `shown .a modification in yvhichithe threadszare..cut.orrelied. into the depth throughout the lengthof tions may be Y to be grasped metal instead of being rolled, as heretofore described. This can sometimes be done when the metal'is of sufficient thickness. It will be observed that I produce the taper in the manner previously described by forcing the metal outward at the base or larger endof the taper', the latter being formedentirely by properly shaping the` Wall of the tube Vand not Aby changing the depth ofthe threads. That is', I maintain the metal wall of a uniform thickness `and the threads a uniform the tapered portion, thereby maintaining a uniform strength `of metal throughout the joint.

The advantages which result from the reinforced joint constitutinginy .present invention will be apparent to engineers. I eliminate the usual coupling member and form a joint havinga strength .equal at least :to that of the Wall ofthe casing. Inaddition to the reinforcement of thel threaded portion, I provide a reinforced clamping portion by which. the casing Vor pipegsections may be manipulated Without injury, thisreinOrcement extending alongntherpipe to Aany desired distance.

Ivhave described .detail theA specific constructions illustrated in thegaccompanying drawings forithe purpose of clearly disclosing embodiments of myb invention butI am ,aware that variousA changes and` modificamade Within .the scope of my broad claims andl Without in any manner departing from the scope'of myv claims. j'

l. A sheetmetal casing for culverts,f.con duits,-vvells and drainagepurposes, comprising a tubular .memberprovided With threaded end portions, one end-being .tapered and the other end being correspondingly. dared so that thctapered end offene sectionmay be Vscrewed into the flared end'ofan adjacent section with an. increasingwedging effeet, and said ends being reinforced throughout .the tapered and forcement being extended also back of the threaded portions to `provide a plain nnthreaded reinforcedportion, :said `piain reinforced portion being, `.of a Width .su-fhcient andV manipulated by the gripping members of a Well-drilling machine.

2. A ksheet metal casingffor conduits, eulverts, wells and drainage-purposes,,comprising a tubular `member `provided with spirally corrugated end portions, one endl being@ ta pered and the other enc being reinforced, the co-rru-gations"extending into-the reinforcement, so .that the tapered-.endfof one section-maybe. screwed :into the reinforced end .of an adjacentsection, thefdiameter of the* easingat thebase of the; tapered portion beingeni-arged so that the. outer end Bof; the

. tapered portionymay Vhare; the vsame internal diameter as that of the casing-.,-

main. part of the flared portions, the reinf` 3. A sheet metal easing for conduits, ou1- verts, Wells and drainage purposes, compris- 111g a tubular member provid d with threadinto the reinforced end of an ad tion, the diameter of the easing at the base of the tapered portion being enlarged so that the outer end of the ta have the same internal the main. part of th ered port1on may 10 'iameter as that of e casing.

In testlmony whereof I aiix my signature.

Witness: i

BENNETT S. JoNEs.

ANDREW SMITH.

addressing the Commissioner o1 Patents, 

